From 2001 to 2007, California's information industries increased their output by 21 percent, but lost 6.9 percent of their jobs. In addition, the jobs these high-tech industries tend to create directly are high-wage jobs that require advanced degrees, while the jobs they create indirectly are low-wage service-sector jobs at homes, restaurants, offices, and hospitals. So, by their nature, they exacerbate the segmentation of California's economy.
From The New Republic.
While I know full well about how our productivity is rising faster then output which means a reduction in jobs, the second part of that which is the divergence between high and low paying jobs being created by, in part, the elimination of that middle tier of workers is something I hadn't seen so clearly stated before.